Mysterious Transmission Failure

Help! My 2006 Tundra double cab 4.7 L has been at the local Toyota dealer since March 12. The problem: when I start out it upshifts just fine. But to get out of our valley means climbing one of two five to seven degree grades. We’re pretty hilly around here in SW Wisconsin.

Anyway, the tranny downshifts to climb the grade but it doesn’t add power. It’s like leaving the truck in eighths gear using a paddle shifter when starting from a standing start, or--old school here--leaving a column shifter in third while climbing a hill. There’s nothing you can do: downshift to 3 or 2 or 4WD—no results. You barely make it up the hill.

It’s been towed to Toyota twice and I’m awaiting the verdict of a “Case Study” or Opened Case with Toyota, or whatever.

Other than this it’s a nice enough truck. But it may not be worth a new, $4,000 tranny.

Any advice?

 

Wishing you all the best with this issue. Keep us posted with your results . . .

 

$4k tranny beats $800/mo. new truck payment. Hope its not tranny.

Report back.

 

Must not have had a trans cooler....

 

I had an issue with my transmission where the replacement part alone cost $1,400. I called the local Toyota junk yards and found a transmission with 119k miles for $700. A local transmission shop replaced it for $700. Total cost $1,400

it was the valve body that went bad on mine and most likely cause I was driving around with an out of balance driveshaft.

 

Sounds like a plan. If that turns out to be the plan; still awaiting word.

 

You mention you are in Wisconsin. How bad is the rust under the truck? If it does in fact need a new transmission, I'd inspect the frame before making that call. Rust is the #1 killer of the 1st generation tundra. I'm hoping it's something other than your transmission since it's only impacting downshifting. That seems really odd.

 

This is not an answer to your problem, but rather some unsolicited advice.

Every dealership I've dealt with charges premium on parts and labor. Most calculate repair hours consecutively vs. concurrent, so if there are two related 2-hour procedures which can be done simultaneously for a total of 2 hours labor, you still get charged 4 hours labor. Once your vehicle is out of warranty, I advise everyone I know to NEVER go to the dealership unless you need diagnostics performed, but make sure the "stealership" work stops there.

Instead, when your warranty is up, seek out a good local Toyota/Lexus-specific mechanic, most average sized towns have a few. A lot of guys get tired of the crap they see at dealerships and will branch out to their own gig.

You may not realize this, but once they've rendered their verdict, you can pay the nominal diagnostic fee, take their report and quote, and carry it ad your vehicle to your preferred Toyota mechanic - you're not on the hook for anything, you can freely go as you please. When they finish diagnostics, do just that - ask them to outline what's wrong, print our a quote on the labor so you have it in-hand, then tell them "I need to chat with my significant other about this, but I'd like to pay my diagnostic fee now". Pay their diagnostic fee, then find your local reputable non-dealership Toyota mechanic to do the work for 1/3 to 1/2 the cost.

I had a case not long after I bought my '06, used, from a dealership in the state next door. Voltage gauge was steadily dropping on the way to work. Stopped at NAPA, got a battery, and a fire started under the hood. It wasn't clear where the fire was, so I had USAA tow it to the nearest dealership so they could run a series of tests against it, inspect for fire damage, etc., I expect them to have the expertise, and if due to a recall, maybe negotiate it out.

Needless to say, alternator died and new battery caused it to catch fire. It was isolated to the alternator itself, no harm or foul to the rest of the truck. ECU and everything else turned out fine, no wires burnt up. I promptly paid their $135 diagnostic fee, then called USAA again and had it towed to my trusty local mechanic who happens to know Toyotas inside and out. I paid just over $600 total for refurb Denso replacement, labor etc. where the stealership wanted thousands. No thanks.

Wait for the dealership to render a verdict. Get a quote on the labor. Pay their diagnostic fee. Find a shop and take your vehicle there.

 

PS - Weird shifting issues can happen if you're too low or too high on tranny fluid, or if you use the wrong fluid. I presume this is the 1st thing you checked before carrying it in. If not, they may or may not find that during the diag, I'd hope they did and told you honestly.

PSS - When you're dealing with specialized cases, sometimes it's better to go to a specialized shop. Transmissions, go to a transmission shop. Air conditioning, go to an HVAC shop. When someone specializes in a specific field, sometimes they can find better, more budget-friendly solutions to your issue. Because that's all they work on, they'll also know about many of the quirks and oddities with your specific type of transmission someone at a dealership may not know.

 

First thing I did was look for the tranny dipstick. There isn't any. It's a sealed unit. Now, thanks to you, I recall in all this excitement that nobody at Toyota has mentioned checking the fluid level. Like, Duh!

 

Have a friend with an 06 DC w/ 200+ K miles on it. . . his transmission was doing all sorts of things . . . completely cutting-out etc.
He was ready to replace it . . . turns out it was a bad solenoid . . . $300 fix.
Not saying that's your case, but it may be something simple.
Please keep us posted.

 

Sounds like it’s slipping in low gear but I’m no expert. Let us know what you find out.

 

Ah! The '06 in your nickname is for 2006, I take it? You're right, '05 and '06 both lack dipstick, if memory serves.

Could be something as stupid as low fluid, or minor as a solenoid. Dealership will be able to figure it out. But just know this if you don't already ... this isn't an arraigned marriage. You're not tied to them to do the work just b/c you asked for a diagnostic. I guarantee you there are probably a dozen competent places within 50 miles of you that'll do the work 100% as well for 50% less than stealership fees.

Dealerships can be great on complex diagnostics but man they're craptastic on their fees. I'd go to the dealership every time if they could just charge parts at-cost (+ offer new and reman options) and give reasonable labor so they're within 25% of what "normal" shops cost.

 

The update so far is there is none from either Mother Toyota or the dealer’s service rep. It’s 1:30 p.m. and I haven’t heard a peep. The silence is worrisome. I think it’s time for me to segue from my usual Mr. Nice Guy. I hate doing that.


But first, thanks for all the good replies. I’ll try to touch all of your bases. I have two backup service providers at hand. It’s only back at Toyota because their first try failed.


And, yeah—on parts cost. I replaced a broken taillight for $75 buying on line. Toyota wanted $260. Center, plastic wheel cap: $19 on line, Toyota $95.


Also, on the rust issue: Toyota recalled it a few years back for a frame recoat. Still, a recheck is in order.


Re: the solenoid and used tranny. Way, way, back, one of my after high school jobs was pumping gar at a repair shop. At five the mechanics went home and I closed at nine. But the transmission repair guy showed up to moonlight after leaving his job at a new car dealer. I learned a lot watching him break down transmissions: valve bodies with debris caught in the channels, etc. He explained how the units functioned—great guy.


Now, sadly, we’re in the replace it culture. Except here on this forum I’m finding evidence that the common sense approach still lives.


Thank you.

 

One other thing. The tech who's been on this since day one thinks it's a throttle issue. But he hasn't been able to pinpoint it. So they asked Mother Toyota to step in.

 

https://youtu.be/Ac7G7xOG2Ag

 

How did you find one of my ground school instructors from Navy Flight Training? Amazing.

 

That description does indeed sound more like an engine issue than a transmission issue. How does the engine run otherwise? Does it drive normally until it exhibits this behavior? Will it rev in neutral?

 

A coworker of mine tore apart his tranny to rebuild it. He told me it wasn’t difficult to do. The hardest part was really just keeping track of all the parts and where they go since there’s a couple hundred parts internally. I guess it would suck putting one back together only to have a few pieces left over.

 

Update II
I have Mother Toyota’s opinion about my ’06 Tundra. There are three air switching valves in the emissions control system that need to be replaced because they’re probably compromised by debris. (This is a farm. The Tundra spends a lot of time off road and going through rough pastures.)


Depending on their condition, additional valves behind them might need replacing. Parts and labor estimate is $2,800.


I told them to hold off a day while I consider euthanizing the truck. Meanwhile, my other repair source is researching the plausibility of Toyota’s possible fix. I’m also interested in all of your opinions.

 

Air switching valves? Is this related to the air pump system? If so, bypass for pennies on the dollar.

 

I was thinking that too. I'm not sure if the bypass triggers a check engine light but it doesn't effect drivability at all.

@Ardunt06Fan , do you have to pass emissions in WI? I believe the bypass he's talking about is made by Hewitt.

 

I'm awaiting clarification on that right now.

 

There are no emissions tests in my part of Wisconsin. I believe I have at least on guy who'll do the bypass. This Tundra spends most of its time off road.

 

Do the bypass, gets rid of limp mode and any other nonsense it's $200 and so easy to do.

https://www.youtube.com/watch?v=WDzNfW7Ti5g

 

Were you getting the check engine light staying on prior to taking it to the dealer?

Did you ever check the brakes for excess heat? Plugged ports in the brake master cylinder (may be caused by the pedal pushrod being adjusted too long) can cause major brake drag as the fluid warms up, but you’ll also get a lot of heat at the brakes.

 

This sounds logical. I immediately thought yours was going into limp mode (when climbing) when I first read the symptoms you described.

 

Tomorrow I'll try to find someone to install the Hewitt bypass. Thanks Rock Climber. Actually, all of you have been helpful.

 

To reiterate, per your description it sounds like the transmission is shifting fine, but the engine isn't reving.

So again:

 

I hope all goes well. I've spent a lot of time in Clyde area (pop. 300, in the Lone Rock, Spring Green, Dodgeville triangle). I know the hills and farms of which you speak.